The purpose of the Remote Accelerator Pedal Sensor (RPS) is to allow an operator to adjust engine speed from a remote location. The RPS functions similar to the Accelerator Position Sensor. For the RPS function diagram, see Figure
“Remote Accelerator Pedal Sensor Function Diagram”
.
Figure 1. Remote Accelerator Pedal Sensor Function Diagram
Note: The RPS sensor, ON/OFF switch and circuit are supplied by the body builder.
Section 38.1.1
Remote Accelerator Pedal Sensor
The RPS is a potentiometer that sends a variable analog voltage signal to the ECM that indicates a desired speed. In order for the RPS to function, the control module must be programmed for remote RPS enable. To activate the RPS, the remote variable terminal of the ECM must receive a 12 volt signal.
Section 38.1.2
Pedal Operation
The pedal receives a 5 volt reference signal and a signal return through the body builder connections. By depressing the pedal, the RPS signal voltage increases, indicating a request to increase engine speed.
Section 38.1.3
Fault Detection Management
The ECM monitors the voltage at the RPS terminal for voltage to determine if the signal is in range. A minimum voltage level is established to verify that the circuit is not open and a maximum voltage level is established to verify that the signal is not shorted to a voltage source. When the ECM detects a voltage out of range, the pedal will be disabled and Flash Code 213 for out of range LOW, or Flash Code 214 for out of range HIGH will be set.
For the RPS function diagram, see Figure
“Engine Speed Without Vehicle Speed Control”
.
Figure 2. Engine Speed Without Vehicle Speed Control
RPS connector voltage checks are listed in Table
“Remote Pedal Sensor Connector Voltage Checks”
. Checks are made with the RPS disconnected and the ignition key ON.
| Test Points | Spec | Comments |
| A to Grd | 0v | A positive voltage reading indicates a short to another circuit. |
| B to Grd | 0v | A positive voltage reading indicates a short to another circuit. |
| C to Grd | 5 ± .5v | Voltage out of specification indicates an open circuit or short to ground. |
| 451A to Grd | 12v | ON/OFF switch voltage when switch is in the ON position. |
RPS connector resistance checks are listed in Table
“Remote Pedal Sensor Connector Resistance Checks”
. Checks are made with the RPS disconnected, ignition key OFF and all accessories OFF.
| Test Points | Spec | Comments |
| A to Grd | > 1,000 Ω | Less than 1,000 Ω indicates a short to ground. |
| B to Grd | > 1,000 Ω | Less than 1,000 Ω indicates a short to ground. |
| C to Grd | < 5 Ω | Greater than 5 Ω indicates circuit is open. |
| 439C to Grd | > 1,000 Ω | Less than 1,000 Ω indicates a short to ground with switch closed. |
Harness resistance checks are listed in Table
“Harness Resistance Checks”
. Checks are made with the breakout box installed on the chassis harness only, and the sensor connector disconnected.
| Test Points | Spec | Comments |
| 5 to B | < 5 Ω | More than 5 Ω indicates a high resistance or an open circuit. |
| 6 to C | < 5 Ω | More than 5 Ω indicates a high resistance or an open circuit. |
| 30 to A | < 5 Ω | More than 5 Ω indicates a high resistance or an open circuit. |
| 36 to 439C | < 5 Ω | More than 5 Ω indicates a high resistance or an open circuit with the switch closed. |
Operational voltage checks are listed in Table
“Operational Voltage Checks”
. These checks are made with the breakout box installed and the RPS sensor connected to the connector.
| Test Points | Spec | Comments |
| 30 to 6 | .5 to 4v | Voltage should be low at idle position and should increase by depressing the pedal. Voltage reading should change smoothly and there should be no position that causes a sudden increase or decrease in voltage. |
| 36 to Grd | 12v or 0v | ON / OFF switch voltage: 12v when ON, 0 volts when OFF. |
Fault code descriptions are listed in Table
“Fault Code Descriptions”
.
| Fault Code | Description |
| 213 | RPS signal was less than 0.488 volts. Circuit open or shorted to ground. |
| 214 | RPS signal was more than 3.91 volts. Sensor shorted internally or short to VBAT or VREF. |
These values are for software version AF. Refer to “38.1.7 Flash Codes”
, for further Flash Code information.
Section 38.1.4
System Description
The remote accelerator pedal sensor is used for engine speed control outside of the vehicle cab. As part of the PTO engine speed control, connections for the RPS are supplied through the body builder connections.
To operate the RPS a 5 volt reference voltage is supplied by the ECM from pin 5 through the body builder connection circuit 916C. Signal return for the RPS is supplied by a dedicated terminal number 6 through the body builder connection circuit 952A. The remote pedal sensor is a potentiometer that uses the 5 volt reference voltage and signal return to supply an analog voltage to terminal 30 through the body builder connection circuit 510. In the idle position, the voltage signal from the RPS is low. As the pedal is depressed, the voltage increases, indicating an increase in demand for speed from the operator.
Before the RPS is operational, the ECM must first have a 12 volt signal at pin 36. This is supplied through the body builder connection circuit 451 to enable the operation of the RPS.
To interrupt the operation of the PTO speed control, if the Remote Variable circuit is open, the engine will return to idle. Or, if the brake or clutch pedal is depressed, or with an automatic transmission the transmission is placed in gear, the engine will return to idle. If the option has been programmed in the ECM for PTO operation, disabling the brake, clutch or transmission will not interrupt the PTO speed control. Also, if the ECM receives a signal from the vehicle speed sensor, the engine will return to idle. Remote PTO speed control will not function if the brake or VSS circuits are in fault. The RPS will not operate if the RPS system has an active fault present.
Section 38.1.5
Programming
The ECM must be programmed to enable the operation of the RPS. From the programmable parameters menu under the option PTO controls, select RPS and program for enable. If it is desired that the cab controls (APS brake and clutch) not affect the operation of the PTO speed control, select the option PTO Operation Disable and select Enable.
PTO mode must be programmed to remote. If the RPS is enabled and there is no pedal signal present, the ECM will log a fault code. The PTO Maximum Engine Speed will allow programming for the maximum engine speed allowed when in PTO mode.
Section 38.1.6
Fault Detection Management
The ECM monitors the voltage at the RPS terminal to determine if the signal is in range. A minimum voltage level is established to verify that the circuit is not open, and a maximum voltage level is established to verify that the signal is not shorted to a voltage source. When the ECM senses the voltage is out of range, the pedal will be disabled and a Flash Code 213 for out of range LOW, or 214 for out of range HIGH is set. If the ignition is shut off, the flash code will be recorded as an inactive code.
Section 38.1.7
Flash Codes
The following flash codes could display when troubleshooting the RPS:
Section 38.1.7.1
Flash Code 213
ATA Code SID 29 FMI 4
Remote throttle signal out of range LOW.
Flash Code 213 indicates that the ECM pin 30 voltage was less than .25 volts. (If this is the AF software version, the ECM pin 30 voltage was less than 3.99 volts.) This indicates an open circuit for the VREF supply from ECM pin 5 or in the RPS signal circuit to pin 30 from the RPS. It may also result from a defective (open) remote pedal sensor.
Section 38.1.7.2
Flash Code 214
ATA Code SID 29 FMI 3
Remote throttle signal out of range HIGH.
Flash Code 214 indicates the ECM pin 30 voltage was greater than 4.5 volts. (If this is the AF software version, the ECM pin 30 voltage was greater than 3.91 volts.) This indicates a possible open circuit in RPS return to pin 6 or a short to another voltage supply on the RPS signal circuit. It may also result from a defective (shorted) remote pedal sensor.
Section 38.1.8
Troubleshooting
The EST ProLink can be used to monitor the status of the PTO controls. Comparing the data list reading to actual operation will indicate if the controls are operating properly. Using the menu option of programmable parameters, the programming can be verified to be sure the ECM is programmed properly for the application. The data list can be used to monitor the parameters that cause the interruption of PTO speed control. Use the Diagnostic Code menu to read fault codes.
Section 38.1.9
Before Troubleshooting
Before troubleshooting, ensure the batteries are fully charged. Check the battery connections and grounds for clean, tight connections, free of damage. The voltage test will give misleading results if the batteries are not fully charged.
Before troubleshooting, inspect the circuit connectors for pushed back, loose or damaged (spread or bent) terminals or wires with cut strands, etc. Wires and connections must be free of damage or corrosion. When some connectors corrode, a light white residue will be present and must be removed.
Before troubleshooting, inspect suspect circuit grounds for clean, tight connections, free of damage.
| Series 40E Troubleshooting Manual – 6SE241 |
| Generated on 10-13-2008 |